Using your driver, swing to the top and stop. Holding the club with your left hand only, flare out all but your pinkie and thumb. If the clubface is square, the club will balance in these two fingers. If the club is unsteady, your left is either too cupped (open clubface) or flat (closed clubface). Adjust your grip according: Strengthen your left hand to fix an open face; weaken it for a closed one. You'll start striping your drives down the middle.